MACAU — It was Sunday afternoon, maybe two hours after a resounding triumph for Manny Pacquiao, and to Bob Arum of Top Rank Boxing, the landscape brimmed with possibility, more so than usual.

Even the impossible — a date for Pacquiao with Floyd Mayweather Jr. — seemed a little less so.

That said a lot about how Pacquiao performed against Brandon Rios, and a lot about how Arum believed his mega-fight foray into Chinese territory had gone. (Macau, like Hong Kong, is a largely autonomous region of China with separate legal and economic systems.) Arum said it had cost more than $30 million to put on the pay-per-view event, but he was not worried about breaking even, regardless of the expected drop in viewership.

Arum stood off to the side of another boxing news conference, and not 15 feet away was the comedian Dave Chappelle. Yes, Dave Chappelle. As Paris Hilton and David Beckham did, he watched Pacquiao batter Rios from the first bell to the last.

Chappelle did not want to talk much about boxing, though he is a fan and a friend of Pacquiao’s trainer, Freddie Roach. But Chappelle did address the sport’s presence in Macau, what it felt like to wake up and walk over to a fight in a casino, halfway around the world, that looks and feels like one in Las Vegas.

“This place,” he said, “is nuts.”

Arum, naturally, had already started to plan Pacquiao’s return to Macau. First, Arum wanted a bout next April in Las Vegas, either a rematch against Timothy Bradley or a date with Ruslan Provodnikov, although Pacquiao is a friend of Provodnikov’s, which complicates matters. Then Arum planned to bring Pacquiao back to Macau next November or so.

As most professional sports leagues push to make inroads into China, Arum provided a blueprint in 2013. He hosted a smaller event in April and another in July, and as fans grew to understand the sport, they also seemed to take to it.

The arena was nearly three-quarters full at 9 a.m. Sunday, and by the time Pacquiao and Rios tangled, the place was sold out, and the fans were loud and vociferous in their support of Pacquiao. Arum described the week in typically understated terms: “A great big artistic success.”

“It’s almost like making a major motion picture, except we open and close, unfortunately, the same night,” he said.

Pacquiao barely made it back to his locker room as a crush of fans descended. One managed to hug the champion, only to end up with broken glasses and a swift trip out the side door. Pacquiao inched forward, one step at a time, and the mob inched with him. They moved as one.

The locker room was bedlam. Everyone wanted pictures with the actor Stephen Baldwin. Periodic chants of “Manny! Manny!” broke out. Pacquiao retreated to the showers, away from all the chaos, away from all the cellphone cameras trained in his direction.

He, too, seemed to enjoy his time in Macau. He did not have to leave the Philippines until fight week — Macau is in the same time zone, and about two hours by air from Manila — and he could keep the money from his purse that is normally taxed — in this case, a guarantee of $18 million with the possibility of about $30 million, without the usual tax reduction of 39.6 percent, Arum said.

Pacquiao emerged from the shower room with his hair slicked back. His face showed few marks, even though the fight had lasted 12 rounds. The crush again descended, but he pushed through and left for blood and urine tests.

While that happened, Roach went upstairs to the news conference, where one reporter from the Philippines grabbed the microphone to tell Roach he was an honorary Filipino. Roach acknowledged that Pacquiao had let up in the final round but said that Rios had survived a knockout more than Pacquiao had avoided handing out one.

He said Pacquiao had fought the “perfect” fight, and then he mentioned Mayweather and their dream blockbuster, the talk of which dominated the boxing world from 2009 until about 2011. Then Pacquiao fell to Bradley in an egregious decision and was knocked out by Juan Manuel Márquez.

Because Mayweather remains undefeated, and because Pacquiao looked like the old Pacquiao, more or less, in the Rios fight, the prospect of a bout against Mayweather resurfaced. Roach noted more than once: “That’s the fight the world wants to see.”

That is true, even if the chances of that happening fall between zero and a number really close to zero. Regardless, when that matchup is discussed as a possibility, even when it is not one, it drives interest from the casual sports fan whom opponents like Rios cannot draw, whom boxers other than those two cannot draw — the allure of the impossible, more or less.

“That fight should happen,” Arum said of Mayweather-Pacquiao. “Particularly after that performance.”

He did not respond directly when asked to estimate the chances that it would happen.

“If everybody wants it to happen, it can happen,” he said (although that “everybody” would include Arum himself).

“I mean, there’s no impediment,” he said (although there are several, most prominently the current cold war between Top Rank and Golden Boy Promotions).

“It’s been done before,” he said (and he meant those generational-type fights, not the best fight that can be made of this generation).

Pacquiao came to the stage last. He ducked a question about Mayweather. He thanked God and his fans and the journalists in attendance. His face looked as if this was a prefight news conference, not a postfight one. He noted how many people had questioned him after the Márquez knockout, how he wanted to reverse the narrative, how he knew he would be back.

“I told them, we will rise again,” he said.

A version of this article appears in print on November 25, 2013, on page D6 of the New York edition with the headline: Pacquiao’s Comeback Inspires Hopes, However Dim, for a Mayweather Bout. Order Reprints|Today's Paper|Subscribe